Juliette Lewis says what no one else will about Misty Upham's mysterious death

Mourning the death of her cast mate Misty Upham, Juliette Lewis made some peculiar revelations that suggest she thinks foul play was involved in the August: Osage County star's demise.

Lewis posted several messages on Instagram talking about the late actress's hard life and how much suffering she endured. "Misty Upham survived many things that many don't early on in life," Lewis wrote.

She added that despite her hardships, Upham was able to remain hopeful, but she always carried darkness with her. "Out of her dark space in which her light got dimmed. I will remember her as tuff. Wise. Funny. Spiritual. And hopeful. This is another great reminder to call and check on someone when you think to. Not when its [sic] too late. RIPMistyUpham."

After Upham went missing on Oct. 5, her father, Charles, told The Hollywood Reporter he feared his daughter could be suicidal after not taking her medication for bipolar disorder. But, upon finding her body on Thursday at the bottom of a 150-foot embankment near the White River, Upham's family did not believe her death was self-inflicted.

"The family has stated that, after seeing the body, they still do not feel that Misty Upham committed suicide," Filmmaker and family friend Tracy Rector told THR.

With her own suspicions, Lewis tweeted some revelations herself, claiming that Upham confessed to her she was actually afraid she could be killed. "Misty told me about horrible violence she suffered on NA reservations She felt she coul [sic] be murdered! Bcuz she was vocal #ThisIsNOTaSUICIDE."

Misty told me about horrible violence she suffered on NA reservations She felt she coul be murdered! Bcuz she was vocal #ThisIsNOTaSUICIDE

Lewis also tweeted she thinks an investigation should be launched into Upham's untimely death, saying that, "#RIPMistyUpham Misty spoke out alot against injustices within Native community. And had known enemies. Police must do an investigation."

#RIPMistyUpham Misty spoke out alot against injustices within Native community. And had known enemies. Police must do an investigation.

Meanwhile, Upham's family is upset because police allegedly refused to help find the missing star after she went missing. Authorities simply insisted there was "no cause for concern," Rector told THR on Thursday.

"When [Misty] disappeared on Oct. 5," Rector said. "The family knew something was seriously wrong — it was out of character for her to be gone so long without being in touch."